


Newton's Third Law of Motion

by thependragonismightierthanthesword



Category: Criminal Minds (US TV), Merlin (TV)
Genre: Alternate Universe - Modern Setting, Angst, Awkward Romance, Crossover Pairings, Crossovers & Fandom Fusions, Hurt Arthur Pendragon (Merlin), Kidnapping, M/M, Protective Merlin
Language: English
Status: In-Progress
Published: 2021-01-18
Updated: 2021-02-08
Packaged: 2021-03-16 04:48:14
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 8,026
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28825467
Author URL: https://archiveofourown.org/users/thependragonismightierthanthesword/pseuds/thependragonismightierthanthesword
Summary: It didn’t matter that he was over 1500 years old and had ridden a dragon; everytime an airplane took off, Merlin was amazed and a little bit terrified.He never had much notice to prepare himself for flights, usually in between receiving that oh-so-familiar “wheels up in 20” text and take off, he only had time to grab his carefully pre-packed bag and travel to the office. He’d like to think that with some mental prep time, the feeling of the metal death tube lifting off the ground wouldn’t come as quite a shock.Then it was over, they were in the air, and Merlin released the breath he had been inadvertently holding. He looked up to find his coworker, Dr. Spencer Reid, staring intently at Merlin’s delicate fingers, which were trying to strangle the armrests.“Nervous?” Dr. Reid asked._______Merlin joined the BAU to catch bad guys and inject some adventure into his life. He didn't expect to find a second family or a new romance, and he especially didn't expect to be called out personally by a kidnapper who claims to have someone he cares about deeply. The only problem - Merlin doesn't have anyone outside the BAU he knows...
Relationships: Merlin & Arthur Pendragon (Merlin), Merlin (Merlin) & Spencer Reid, Merlin/Arthur Pendragon (Merlin)
Comments: 12
Kudos: 101





	1. In Which our Heroes Solve a Case

**Author's Note:**

> Mild references to violence. About what you'd expect from a Criminal Minds episode, but with no graphic descriptions. This is part one of a two, maybe three, part fiction. I don't know if there's even a market out there for Criminal Minds/Merlin fic, but this idea stuck in my head and was a fun distraction from the more angsty fic I'm working on! Hope y'all enjoy, part two coming soon.

It didn’t matter that he was over 1500 years old and had ridden a dragon; everytime an airplane took off, Merlin was amazed and a little bit terrified. 

He never had much notice to prepare himself for flights, usually in between receiving that oh-so-familiar “wheels up in 20” text and take off, he only had time to grab his carefully pre-packed bag and travel to the office. He’d like to think that with some mental prep time, the feeling of the metal death tube lifting off the ground wouldn’t come as quite a shock. 

Then it was over, they were in the air, and Merlin released the breath he had been inadvertently holding. He looked up to find his coworker, Dr. Spencer Reid, staring intently at Merlin’s delicate fingers, which were trying to strangle the armrests.

“Nervous?” Dr. Reid asked, with what looked like the hint of a smile tugging up the corner of his lips. 

Merlin felt that familiar heat blooming in his cheeks. Since he was promoted to the BAU a few months ago, Dr. Reid had been the surprising new source of Merlin’s blushes. He was a handsome man, and intimidatingly smart, but after sharing a fumbling, drunken kiss following a team trip to a karaoke bar, Merlin couldn’t bring himself to meet the man’s eyes. But now, here he was, looking at Merlin like he was trying to drink him in and starting to move towards him. 

“Newton’s Third Law of Motion,” Dr. Reid said, sliding into the seat next to Merlin. 

“What?” 

“Newton’s Third Law. It’s how the plane takes off. The engine of the plane shoots hot exhaust backward, pushing the plane forward, which creates a moving current of air over the wings of the plane. The shape of the wings then pushes the air downward, which lifts the plane into the air. Makes perfect scientific sense, but seems like magic.”

“Right. Magic,” Merlin said. 

It had been nearly sixty years since he’d practiced magic (besides using it to forge documents, and that was so commonplace now he didn’t truly consider it magic). It had been too long since he let that familiar warmth of it take hold inside of him as he whispered words in a dead language. In his first life, his true life, he’d used it only for Arthur, and something about that felt sacred, so once his friends had all been buried, once everyone forgot the powers of Emrys the Great, he’d elected to use it only when he truly needed it to save a life. Of course, magic was a part of his very being, a part he couldn’t separate even if he tried, and it yearned to break its dam and flow through him again, an unstoppable rushing river of power and light. He longed for that feeling, but he’d put it on the shelf until Arthur returned, and after World War II, he’d long since given up on his king’s return. After all, when could the world possibly need him most if not then?

“You’ve got a funny look on your face,” observed Dr. Reid. “If I had to guess, I’d say you’re feeling nostalgic? Are you missing something?”

“Ah, you caught me,” Merlin said lightly, trying to play it off. “I’m missing your magic tricks.”

“Really? I have a deck of cards on me, I could show you a couple?” Dr. Reid said excitedly. When he looked up, he found Merlin smirking at him. “Oh...you’re joking.”

“Maybe,” Merlin answered. “But you can show me whatever you’d like.”

This time, it was Dr. Reid’s turn to blush, and then they settled in for the long flight to Oregon.

The trip was nothing new. A body had been found in Portland, dumped in a construction site and missing only the ring finger on the left hand. The signature was recognized as soon as the report came in and ordered an immediate dispatch of the team. According to the strict SSA Hotchner, Merlin’s new boss, the unsub’s pattern was to kill three times in the span of a week and then go underground for five years, leaving them only a few days to catch him. Merlin liked the accelerated time table and the pressure of the situation. It reminded him of his past, helped him to catch hints of that old exhilaration. 

He’d tried loads of things in his years on Earth. When he discovered the unfortunate truth that he didn’t age, he knew that meant he couldn’t do any one thing for too long, or people would start to get suspicious of him. He’d been a tailor, a shoe-maker, a coal miner, a soldier, a hermit, an author, a playboy, a bookseller, and most recently, before this gig, a college professor. The transition to FBI agent felt natural, though it had taken him years to climb up in the ranks. Though he was a “prodigy” in the words of Hotch, he wasn’t quite a Dr. Reid level prodigy and he needed to appear to be at least in his late twenties. While it would have been easy to alter his appearance with magic, it went against his principles, so he’d taken to adding a tiny touch of grey to his hair with dye and when he didn’t achieve them naturally, filling in the dark circles under his eyes with makeup. 

The promotion to the BAU had been a dream come true for Merlin. It was challenging and rewarding and haunting, yes, but he felt like he was adding something of value to the universe again, saving lives and hunting villains. And, an unexpected benefit - the team resembled something of a family. The long days away, the lonely nights in shitty hotels, the shared trauma. They understood each other, they loved each other, they would do anything to protect one another. Though they had yet to fully accept him into the group, it still felt reminiscent of his first found family. He saw whispers of Morgana in Prentiss, hints of Gwen’s kindness in JJ, shadows of Arthur’s strength in Morgan. Garcia was an entirely new beast, but one who had made him feel so welcomed and so loved from the instant he walked into the conference room. Merlin was starting to feel like he had found another home.

The flight from DC to Portland was a long one, and while Merlin had spent some time reviewing the details of the case (nine past victims, staged dump sites, implied resentment against marriage), he’d also fallen asleep, and it was with embarrassment that he peeled himself off Dr. Reid’s shoulder as the plane started its descent. 

“How long was I out?” Merlin asked, trying to sneakily check the shoulder of Reid’s suit to ensure he hadn’t drooled. 

“An hour or so. I didn’t mind,” Reid answered. Merlin was almost sure Reid was telling the truth, he had been the initiating party of the karaoke kiss, after all, but he was still embarrassed. What would the rest of the team think? He could just hear Hotch calling him into his office... 

But before he could dwell on it too much, the plane landed and they were off to the Portland Police Bureau’s East Precinct.

The case, for the most part, was a familiar one. According to the lead detective on the case, the victims were all mid-twenties blonde women in serious relationships but not yet engaged or married. They were all staged in semi-public, lower risk dump sites: houses for sale, construction sites, roadside bathrooms. What was so interesting, to Merlin at least, was that the killer went dormant for five years in between kill streaks. First, there was the why. Three bodies in seven days, and then five years of nothing. What was the symbolism in the hiatus? Then, the how. The victims had all been stabbed, indicative of a sexual aspect of the crime. To take that sexual thrill in killing, and then to be able to restrain from deviant behavior for five years...the cooling off period was unique for sure.

They all had their roles on the team, the one thing they could do better than anyone else. If he was asked to put into words what he brought to the table, Merlin couldn’t have done it in an articulate way. He just had strong instincts that were very rarely wrong and he could see the connections between things. Dr. Reid called it “a knack for the ‘why’.” Merlin thought that a more accurate explanation was “when you live 1500 years, you learn how people act,” but he could never say that out loud. His team had learned to just trust his impulses and not ask too many questions, so they sent him off with Prentiss to interview the victims’ families, hoping they could figure out where the unsub was meeting them and if there was anything else to link them together. 

~*~*~

It was late when they arrived at the hotel, and Merlin had just gratefully sunk down into the uncomfortable upholstered chair in the corner of his room with a glass of scotch when there was a knock at his door. 

He flung it open to find Dr. Reid, holding his own glass of wine. 

“Hi. Can I come in?”

“Of course,” Merlin said, opening the door wide. “How’s your geographic profile coming?”

“Fine. Good,” Reid answered, and then took a breath before diving into the details. “The connection of the bus line between dump sites indicates a comfort zone for the unsub, I’m guessing he lives on the line too. But the victims didn’t, they came from all over Portland. The most recent actually lived in Vancouver. I think he’s meeting them somewhere near the bus line, and if I can figure out where he’s meeting them, that’ll lead us straight to him.”

Reid had been pacing while he spoke, but when he finished, he plopped himself down on the bed. 

Reid, on his bed...the situation definitely lent itself to not-unpleasant but very distracting thoughts. Merlin shook his head slightly, trying to refocus on the case. “Sorry, I forget...but, we think the victims are still alive on the bus, right? He’s not transporting bodies?”

“Right, he’s killing them near each dump site and then bringing the bodies there and staging them. Probably a forensic countermeasure,” Reid answered. “How did the interviews go?”

“Actually really well, I think. Interviewed the boyfriends of our most recent victim and one of the women from five years ago. Both men were actively ring shopping and getting ready to propose at the time of the murders. They went to different stores though, so no obvious connection there.”

“Hmm…” Reid let the word bleed into a quiet that lasted a few moments. “Maybe we could table case-talk for a bit?” he asked, scooting closer to Merlin on the bed. 

“Maybe...”

“Have you read any good books lately?” 

“Um, it’s been a while,” Merlin replied nervously. Two books always took up the same corner of his suitcase: a dog-eared, well-loved copy of TH White’s _The Once and Future King_ and a pristine, leatherbound incredibly expensive copy of Sir Thomas Mallory’s _Le Morte de Arthur_ , which never failed to make him weep. To see his own stories, his own life, immortalized and bastardized by text, and incorrectly in many places….well, it was enough to make any man suspicious of books. He knew there was a kernel of truth in every text and the detective in him made it impossible to enjoy things when he couldn’t draw clear black and white lines between the facts and the fiction. “Kind of hard to read when real life is more interesting than books.”

“I’ll drink to that!” Reid said, smiling and downing the last drops of wine. “Me, I love a good romance novel.”

Was Reid flirting with him? Merlin had never known the young doctor to be forward or even all that interested in any connections of the romantic sort. And yet...what other explanation could there be for this evening? Reid, showing up unannounced and drinking at his hotel and not wanting to talk about the case…

Merlin looked at him, really looked at him, trying to put those people-reading skills to the test. Dr. Reid was not the type of man he would normally go for. He was too thin and too sweet and too smart. Reid’s pupils were dilated slightly and he was leaning in almost imperceptibly towards Merlin. He had long eyelashes, Merlin observed, and then he too was leaning in towards Reid. 

Their lips met, gently at first, curious in their soft pursuit of each other. He felt the slight scratch of Reid’s stubble against his cheek and Merlin brought his hand up to the other man’s jaw, fitting his palm around the sharp edge of it. There was something melancholy about the kiss. It seemed to be the brushing together of two ships in the night, two ships who had suffered the loss and longing and loneliness of the sea for far too long. There was no fire behind it, but a magnetic inevitability, the moon pulling the tide to shore. When it ended, neither of them had pulled away, but instead drifted apart, their noses touching but not their lips. Merlin’s hand slid down from Reid’s cheeks and the moment ended with the same hazy magic that began it.

“Wow. Best kiss I’ve had this century,” Merlin said jokingly, breaking the silence that had settled over them.

“This century?” 

“Yeah, sorry, it didn’t quite top the smacker I got from Sarah Larson,” Merlin said lightly. “My kindergarten crush.”

Spencer Reid laughed, but there was something odd about the way Merlin spoke, and if he didn’t know any better, Reid might think Merlin had seen the better part of multiple centuries. There was just something so timeless about the way he spoke, the way he carried himself, the way he took up space. 

“I’ve wanted to do that for a while,” Reid admitted. “Kiss you for real.”

Merlin could feel that under the cold snow he’d allowed to accumulate over his heart, something was blooming. It wasn’t that there hadn’t been others; there had been many men and a few women through the years. But after the first few, Merlin learned to keep his distance, to never truly give in to a complete love because there was a possibility Arthur would return and an inevitability that he would have to watch them grow old and die or leave before they noticed he wasn’t accumulating the wear and tear of life on his face. When he was a kid, he’d smiled all the time, hoping he would one day be the kind of man with crows feet marking years of laughter. Those cards weren’t in his deck.

“I wanted it too,” he murmured, giving in to his swelling hope and desire, and then they were kissing again, kissing with laughter and wonder like they’d just discovered kissing was possible. 

~*~*~

The next day brought new discoveries. After a great night but a terrible night’s sleep, Merlin was pleasantly surprised to find the wheels in his head were still turning. He hadn’t figured out what connected the victims, but he’d woken with the taste of Spencer in his mouth and the theory that maybe the unsub wasn’t completely dormant during his years in between sprees. 

“What if,” Merlin asked Garcia, who was on speaker phone in the room the police had given them to meet in. “What if he’s racking up smaller crimes to sate his appetite? We profiled the stabbing as having a sexual component...can you look for sexual assaults that have taken place in the dormant periods?”

“That’s a start, but this is Portland. I’m going to need a lot more to narrow it down,” Garcia responded, her normally chipper self. 

“The victims would be engaged or in a long term relationship…” Merlin started, and then Dr. Reid chimed in.

“The locations of the attacks would be near that bus line.”

“Okay, plugging that in...Holy cannoli, you were definitely on to something. There’s almost fifteen unsolved, reported assaults in that time. No DNA evidence at any of the crime scenes.”

“Any physical descriptions of the unsub?” Reid asked, drumming his fingers against his thigh in concentration.

“Yup! They said he had his face covered, but a few women said his bandana slipped below his nose and they were able to give descriptions. Sending the composite sketch to your tablets now.”

“Garcia? Did the victims say where they met their attacker?” Merlin said, starting to get a hunch. 

“Let me look...um..Yes! At least four of the women thought they’d met him at a bar earlier in the night. Different bar every time, unfortunately. It looks like the police showed the composite to bartenders at all four places, but no one could positively ID the suspect. Too bland of a face I guess. 

“Thanks, Garcia!” Reid said.

“Tell Morgan I miss his sweet, sweet-” she started, and Merlin promptly hung up the phone. He still felt a burning embarrassment of intrusion when Morgan and Garcia spoke, even though JJ had assured him this was just how they were. He looked over at Reid, who was deep in concentration, probably putting together some obscure details that would have gone over everyone else’s heads, and then Hotch was striding into the room. 

“A second body’s been found,” Hotch said. “Same signature but more stab wounds and the crime scene was much messier. The finger was cut off ante-mortem instead of post-mortem. I think we’re ready to deliver the profile.”

They both nodded, taking a second to process the facts, and followed him into the briefing room where the police officers were gathered.

“We wanted to get a profile to you as quick as possible,” Hotch started. “This unsub has has now killed eight women and we only have one chance left to catch him before he goes underground again.”

“We believe our unsub is a Caucasian male. We believe he was the same age as his victims when he started killing ten years ago. That would place him between 30-35 now,” said JJ.

“On the surface, he’s a model citizen,” said Morgan. “He’s environmentally conscious, friendly, can hold down a low-skill job and may be a salesman, bar-tender, or service worker. These women feel comfortable enough to chat with him, reveal personal details.”

“We believe he’s finding his victims in bars,” added Reid. “Not dive bars either, respectable, trendy places that would be a draw for women who don’t already live in the neighborhood. If we look at the dumpsites and the bars named by the rape victims, that places his hunting zone and probably home within _this_ radius.” 

“He might flirt with the victims. He comes across as charming at first,” Merlin interjected. “But he’s got a dark side he can’t control. He’s angry, sees women as sexual objects to be used and also as inherently trustworthy. He may have suffered a broken engagement or been cheated on right before the murders started. Maybe the victims are flattered and show interest in him at first, and he thinks he’s enacting justice by killing them.”

“We haven’t identified the locations of the kill sites yet, but we think he’s luring them there, killing them, and then transporting the bodies,” Prentiss said. “The sexual assault victims were victims of opportunity, they all lived in the neighborhood and he followed them. The murder victims are different. They lived in different parts of the city, and somehow, he found a way to lure them away from the safety of the bars and sometimes even their friends to dangerous kill sites. If we can figure out how, we find the unsub.”

“I’m sending a statement to the news agencies right after this, advising women to travel in pairs and avoid bars in this area for the next week,” JJ said, flipping through her notes. “Please increase patrols in the kill zone, and assign officers to go undercover at the places on this list that will be distributed and take note of any sexually aggressive men in their late thirties who are hitting on younger women.”

“We’re lucky enough to have a composite sketch,” Hotch said, wrapping up the profile. “Someone will recognize this man. Canvas the kill zone, focusing special attention on high profile or trendy bars. This man is a flirt, and he may have made women feel uncomfortable before. Ask if anyone has reported anything suspicious, like being followed or invited somewhere under circumstances that made her feel uncomfortable. Thank you.”

The BAU stayed to answer a few questions, provided a few more hunches and guidances, and then regrouped for lunch at a deli a few blocks away. Something had been eating away at Merlin since the delivery of the profile. It was one of those pesky instincts of his, and he knew if could figure out exactly where it was leading him, they might find the unsub. Midbite of his BLT sandwich (a miraculous intervention, bacon) a line of thought came to him.

“Prentiss, what could possibly lead you to leave a bar with a strange man?” he asked.

“There’s not much a man could do to convince me,” she quipped, and Merlin noticed JJ smiling down at her soup. “But the obvious answer is sex.” 

“Okay, sex. Right. But all of these women were in happy, serious relationships, right? And we profiled this guy as being charming. But I doubt he’s charming enough to get three women in a week to step out with him after just one conversation.”

“Step out? You sound like my grandparents,” Prentiss replied. “But what are you getting at?”

“What if he’s not meeting his murder victims for the first time at the bars? What if they’re dates? It would explain why these educated women are going out of their own comfort zones to bars by themselves. That always seemed weird to me anyways.” 

“Okay, let’s say that’s the case…” Reid said, narrowing his eyes. “The dump sites and kill zones aren’t in the most residential areas. Maybe they get on the bus to go home with him, but how does he get them there? And where is he meeting them first?”

There it was again, that prodding feeling. He was on the right track but he was missing something...

“What were the victims wearing when they were found?” Merlin asked Prentiss. He hadn’t gone to the crime scenes. One might think corpses wouldn’t phase him, he’d seen so many, after all, but the opposite was true. He’d had his fill of death and blood and horror, and the least favorite part of his job was seeing more firsthand, so he tried to avoid it whenever the job allowed. 

Prentiss pulled her phone out of her pocket and scrolled through a few pictures. “Huh. All of them were wearing dresses in shades of blue, that’s interesting.”

That felt like half of the puzzle piece he needed, but he was still missing something. Reid was sitting across the table from Merlin, a look of deep focus plastered on his face. 

“What...what undergarments were they wearing?” Reid asked slowly.

Prentiss flipped through a few more photos on her phone. “Matching red underwear and bra, all of them. Lacy, too.”

Under the BAU, his life had become too busy for hobbies of a normal fashion, but Merlin liked to make time for one small hobby: cataloguing the facial expressions of one Dr. Reid. There was his pursed look of concentration, his tight grimace of pain, his expansive, pearly white smile of pure joy that emerged so rarely. But the face Merlin liked best was Dr. Reid’s expression of knowing satisfaction. It crept across his face slowly at first and then clicked into place all at once, aligning his features in a glorious constellation of certainty. Merlin saw that expression start to take hold of the young doctor’s face and then the final piece of the puzzle fell into place in his own mind and they spoke the answer in unison.

“Blackmail!”

“What?” Prentiss asked, a few steps behind, but Merlin was already excitedly dialing Garcia.

“Hello, sweet thing, what can the wizard of the Web do for you?” she said smoothly.

“Do you have access to the victims’ phones and internet history?” Reid asked, getting it out before Merlin could.

“No one ever warns me I’m on speaker phone,” Garcia complained. “But yes, I have their internet history?”

“Did any dating sites or apps show up?” said Merlin

“Not that I can see….Oh! Wait one minute...Ooh, this is good,” she mused, keeping them in suspense. “It looks like each and every one of our victims deleted the same app from their phone the day before they were killed.”

“And what was the app, Garcia?” Prentiss said, still playing catch up.

“Ashley Madison.”

And suddenly everything was clear to Merlin.

“The victims could all see marriage on the horizon,” he said. “Maybe they even caught their boyfriends ring shopping. They were looking for a discreet affair, a little fling to make sure they were doing the right thing by jumping into marriage.”

Reid jumped in, adding to the theory and they began to alternate sentences. “Our unsub was engaged once. He probably already bought rings. I’m guessing they’d been together a while. Maybe even-”

“Five years,” Merlin finished. “Then, he found out she’d be cheating and broke the engagement off. These women are surrogates for her, the fiance.”

“They meet on the app, chat for a while, maybe even go for drinks, and then he gets something from her. A last name, compromising pictures, anything he can use to blackmail her.”

“And then, when he hits his killing cycle, he has material he can use against her. He threatens to reveal the truth to her boyfriend. He tells her to wear the red underwear and the blue dress and to meet him at the bars.”

“She thinks he just wants money or possibly to have sex once.”

“That’s why she follows him to these abandoned locations! If she doesn’t, he’ll tell the boyfriend. And she’s already in this deep, so she thinks she might as well see it out to the end.”

“Then, he kills her. It’s a sexual thing for him, the stabbing. He’s cheapening her, devaluing her, ruining her.”

“And that’s how he picks the dump sites,” Merlin said. “He wants her found and he wants to make her look bad.” 

“Garcia, can you check if any of our victims had overlap in matches or men they were talking to?”

“Yes! His profile gives his name as John, but I’m running the IP address and….Bingo! His real name is Alex Graves. He applied for a marriage license 11 years ago, but it looks like he never got a marriage certificate. There’s no car registered to him and he lives smack dab in the kill zone. I think this is our guy,” Garcia said, typing furiously. “Sending his address to you now.”

~*~*~

Prentiss tossed a $100 bill on the table and they were on the move, grabbing their coats and rushing to the black SUV waiting patiently for them in the parking lot. Driving was another one of those modern miracles that never ceased to amaze Merlin, but when it was Morgan driving, he experienced a lot more terror than amazement. But of course, JJ went with Prentiss and Rossi had declined lunch and was back at the precinct going over files with Hotch, so Merlin reluctantly piled into the back of Morgan’s car, letting Dr. Reid take shotgun. 

Morgan’s driving may have been scary, but he was fast, and it felt like it took no time at all to reach Graves’ house. It looked normal, Merlin thought. Boring and normal. As he got out of the car, he touched the gun on his hip, knowing he should draw it and not wanting to. He missed the days when you could settle things with a swordfight and weapons of mass destruction couldn’t be stored discreetly on your belt. He liked that Reid hated guns too. Another thing they had in common. 

Prentiss pulled into the driveway and as JJ got out, she motioned Merlin and Reid to follow her around back as Morgan and Prentiss approached the front door. The familiar buzzing of an adrenaline rush hummed in Merlin’s chest and he followed her to the back door, crouching to go unseen from the windows. His senses were heightened now. He heard Morgan pound on the door, shouting “FBI, open up.” And then there was movement, a man flying out the backdoor. Merlin took off after him, unsure if JJ and Reid were going to follow in pursuit. He had long legs and was in great shape, so while the man had a few second head start, Merlin caught up to him quickly, and before he could even think, he’d launched himself at the man in flying tackle, flinging him to the ground. 

It didn’t take them long to wrap the case. A quick glance at the man’s wallet confirmed that he was indeed Alex Graves and their preliminary search of his house and phone turned up more than enough evidence to convict. He had lewd photos from most of the victims saved on his phone. He’d taken trophies from his rape victims as well, as confirmed by a collection of necklaces and rings that certainly did not belong to him. The most damning piece of evidence, though, was the bag in his freezer containing eight ring fingers, with room for a ninth. Merlin knew even the best attorney couldn’t explain away that. 

After wrapping up what Merlin considered the boring part of the case (booking the suspect, cataloging evidence, filling out a seemingly endless stream of paperwork), he was finally able to let go of the gory particulars and instead focus on a more pleasant line of thought: Dr. Reid. They hadn’t spent the night together, but they had spent a few hours alternating between kissing and sharing their deep thoughts about philosophy and art and history. Merlin shared his love of Shakespeare, talking about the Bard like they’d been best friends, and Dr. Reid told Merlin his favorite guilty pleasure read: _Fifty Shades of Gray,_ which had made Merlin blush furiously. As Merlin packed his suitcase in the hotel room, he tried to take special mental note of it, of the way the red comforter had creased under the weight of Reid, of the fluorescent lamp Merlin had switched off and Reid had promptly switched back on. He’d claimed he was scared of the dark, but Merlin had the sneaking suspicion Reid just wanted to look at him. It was this particular reverie he was lost in when his phone rang.

It was Hotchner. “Merlin. Are you packed? We need to leave immediately.”

“Immediately? I thought we were going for a drink first?”

“Plans have changed. Can you be ready to leave in ten?”

Merlin nodded, then realized Hotch couldn’t see him, and squeaked out a “Yes, of course,” as he tried to guess why their departure had been moved up by hours. He threw the rest of his clothes into his suitcase, double checked he had both of his books, and did one last check of the bathroom to ensure he hadn’t forgotten his conditioner (another one of his favorite modern inventions.) 

Maybe they had another case, but if that was the answer, why hadn’t Hotch just said so? What couldn’t be said over the phone?

He tried not to think about it, instead did his final sweep of his room and rolled his suitcase to the lobby. The rest of the team was there, looking equally confused about the change of plans, and Merlin knew he wasn’t going to find answers until they met Hotch at the airport. On the way, Dr. Reid chattered away to him, praising his insight on the blackmail, and talking through some of the finer details of his geographic profile that he was proud of. Merlin tried his best to pay attention, but an awful weight was growing in his stomach. He had a sinking feeling that something in the world had shifted, and things at the BAU would not be going back to normal after today.

He was right. 

As soon as they reached the airport, finding Hotch prowling back and forth like a panther as he waited for them, Merlin knew. Something terrible had happened and it involved him. Sure enough, as soon as they boarded the aircraft, Hotch pulled him aside.

“A box was delivered to your office,” he said in that low voice that Merlin had come to notice meant nothing good. “There was no return address and Garcia was suspicious, so she opened it. There was a ransom note inside, Merlin.”

“A ransom note?” 

“Yes. It lacked detail, but the unsub is claiming to have kidnapped someone close to you. Do you have any family in DC?”

“No,” Merlin said softly. “I don’t have any family.”

“Friends? Anyone you spend time with outside of the BAU?”

Merlin was ashamed to admit it, but no, there wasn’t. So just shook his head. “I’m kind of a loner. I can’t think of anyone I’d pay money to get back.” 

“There was an audio recording in the box,” Hotch said. “Garcia sent me a digital file of it. Would you feel okay listening to it?” 

“Of course,” Merlin answered, flipping through options in his head. He chatted with Jenny, a Starbucks barista sometimes. And there was the crotchety Greg, his landlord. But no matter how fast his mind raced, he couldn’t come up with someone an unsub might think he would pay a ransom for. 

Hotch pulled out his phone and pressed play and for the first time in months, Merlin didn’t flinch when the plane took off

“Hi? Um, hello? I don’t...I don’t know if you remember me, or if you’re even the person I think you are, but I’m supposed to tell you that I’m alive and unhurt and, um, you will be contacted with more instructions. And I’m supposed to say that if you don’t do what he says, he is going to...he’s going to pull each of my teeth one by one and mail them to you.”

Every muscle in Merlin’s body was made of ice. The voice on the tape was one he thought he’d only ever hear again in his dreams. The voice on the tape was Arthur’s.


	2. Newton's First Law of Motion

**Summary for the Chapter:**

> Arthur has returned to life...the once and future king with no kingdom and little memories.

**Notes for the Chapter:**

> Sorry for the long wait and shorter chapter! School's started back up again for me which is making it harder to write long chunks, but I'm excited to share this next update.

Newton’s First Law of Motion states that a body at rest will remain at rest unless acted upon by a force. For so long, Arthur’s had been a body at rest. He didn’t remember the moment he died and he didn’t remember the moment his manservant had sent him out into the lake in a small, wooden boat, but he did remember the gentle tug on his arm, the slow falling, the ever-present drift into oblivion. He was never conscious during this drift, for that would have been a torture - alive, underwater, alone - and his experience certainly wasn’t torture. In fact, it was almost pleasant, but for a nagging sense of loss that lapped persistently at Arthur’ edges. 

When Arthur rose from the surface, sputtering out water, gasping on cold air he hadn’t tasted in oh-so-long, he knew a great amount of time had passed, but he couldn’t have guessed at what that  _ meant  _ for the world. He climbed to the shores of the lake, gaining strength in his legs with each step, and he saw that for miles in every direction, there were things to marvel at. His transplantation back into the world had been an overwhelming thing, his senses constantly assaulted with the angry grumblings of the city and the bright headlights on the speedy horseless carriage referred to as cars. 

The most disorienting experience was that of his memory. It had split in two. There was a past that felt clear and precise, each color bright and each line sharp. There were faces preserved here that he could tell he missed, but yet he felt largely disconnected to this sharp past, that it was a definite island, but he could drift away from it into the waves of the blurry, more recent memory. He hadn’t lived through it, but he had existed through it, and he had a soft sense of the Bubonic Plague, The Renaissance, the Industrial Revolution. World Wars, bombings, horrible injustices and acts of terror. All this he could float through and not feel totally unmoored in his new surroundings, and it became comforting to leave behind those clear faces he would never see again for the hazy recollections and the cold present. And so, Arthur abandoned his title and his duties and his destiny, exchanging them for a simple and soothing life as a farmer. 

The necessities of the world revealed themselves to him easily. When he walked ashore, he needed clothes to replace his armor and he found, lying against a tree, a pile that suited the modern sensibilities. He needed shelter, and he came across an empty and modest cabin on a patch of land a few miles out of a village and it was here that he began his life anew. He gradually became a social creature, making friends at the bar and the coffee shop and the library. He enjoyed humble pleasures that had never been available to him in the past, sipping tea and reading fantasy novels for hours on end. He learned to cook, he learned to give dramatic speeches, and he learned to knit. 

Arthur stitched together 40 years of this peace. He had to move, twice, when his friends noticed that silver never found its way to his hair and his bones never bent with age, but, like they had been upon his arrival, his needs were always provided for if he only asked the world. It was the second move that had taken him across the pond to Washington, D.C. He had been feeling lonely in the last few years, lacking in roots and in company, so he picked an apartment in the center of the city where he could hope to meet more people, and if nothing else, feel less alone. 

But despite his best efforts spent chatting up women at a coffee shop and dancing on closeted Senate staffers in bars, DC was proving as fruitless as his last homes. Arthur was shopping for plane tickets to New York, about to call it quits on DC, when a ghost strolled past the window of the coffee shop he was sitting in. 

The ghost wore the face of the man who sprang from the depths of Arthur’s memories. Blue eyes, raven feather hair, angular cheekbones, wiry frame...and the way he moved. He reminded Arthur of the elf from The Lord of Rings, which Arthur had recently seen and become obsessed over. It had been an instinctual move, almost a magnetic one, to follow the man. Down a few streets, through a wooded park, to an older neighborhood of town, and then disappearing into a brick apartment complex. The more Arthur observed the man, traced his steps and watched his stride, the more solid the man seemed to become. Not a ghost, but still one who walked the Earth like he had been on it for too many years.

It became a routine of Arthur’s to follow the ghost, now that he knew where he lived. He’d lurk outside the apartment and trace his steps. He learned the man worked for the FBI, learned he had no significant other or friends, learned he liked to browse bookstores but never bought. The ghost drank sugary, extravagant coffees with names like “Unicorn Frappuccino” and “Toasted Marshmallow S'mores Latte” and from a cup he’d tossed (and Arthur had immediately snatched from the trash), he’d learned the stranger-not-stranger’s name was Merlin.

This dance had gone on for months. There had been times when Merlin looked over his shoulder and Arthur had to bow his head or duck into doorways and there had been times that he’d almost worked up the nerve to introduce himself. To pass the time, Arthur said in his head the name he’d seen written in pink cursive on the cup, and he had the sense he’d said it thousands of times before. It was only by miracle that anything changed. A new barista was working at one of Merlin’s usual haunts, a cute man with slightly crooked teeth and a masculine jaw. If Arthur really squinted, he thought the barista looked a little like him. He’d gotten to the coffee shop before Merlin, knowing his routine, and he’d staked out his table in the corner that hid his face but let him see Merlin in the reflection of the shop’s window. Through the glass, he saw Merlin flash a clever smile at the barista while paying, and scribble his number on a napkin. Arthur was watching closely though, and he saw the paper blow off the counter and skitter across the floor, landing as if by magic next to Arthur’s toe. He scooped it up greedily and found a number on it and a full name: Merlin Emrys. 

From this moment on, a compulsion possessed Arthur. His fingers itched, his tongue burned. He needed to call the number, talk to Merlin. He wasn’t brave enough to do it in person and lead with his face, but he could call, and he did. Over and over he called, but each time, he hung up before he could hear Merlin’s voice. On the day his quiet, longing existence came crashing to a grinding halt, he had called from his normal telephone booth, strategically chosen for its proximity to Merlin’s apartment in case, for some reason, he wanted to hurtle out his apartment, cross the street, and find Arthur readily waiting. This time, Arthur made it past two rings. He was about to hang up when the unexpected happened: there was a voice at the other end of the line. 

“Hello? Hello, is anyone there?” Merlin said. “Hello?” 

But Arthur could not answer because the entire world was swirling around him. He knew that voice, he knew it, he had heard it calling to him in his years underwater. Every so often, that voice - screaming Arthur’s name, crying Arthur’s name, whimpering Arthur’s name through choked sobs. That voice was everything. And then Arthur was fainting, but it wasn’t because a love that had simmered through a millennia was roaring back to life. It was because someone had opened the door of the telephone booth and pressed something over his nose and Arthur was falling, back back back into the darkness and their arms.

~*~*~

For so long, there had been no action in Merlin’s life, only existence. Now, as a force had pulled him toward action, toward happiness, toward a life that once again had meaning, it was accompanied with an equal and opposite reaction-Newtons’ Third Law of Motion. 

In his first few centuries on Earth, he’d assumed that the return of Arthur would be the best day of his life. The once and future king, back in the world of the living at last, accompanied by trumpets and fanfare, overjoyed to reunite with his loyal servant who had been waiting all these years. And he had. Merlin really had waited all this time, never letting himself get too attached to any place or too close to any person, and always holding onto those golden days of Camelot. But now, he had taken one step away from stasis, one step away from waiting, one step away from Arthur, and the laws of motion would not stand for it.

“Merlin?” Hotch asked, yanking the man out of his reverie. “Merlin? Do you recognize the voice?” 

How could he possibly answer the question? Of course he recognized the voice. It had been over a thousand years and he still recognized the voice from the first “Hi?” But he could sense the rest of the team listening in, even if they were trying not to, and he knew if he tried to explain anything about the situation, he would seem like a crazy person and they’d send him off to an asylum and he’d never see Arthur again. But if he claimed he didn’t know the person on the tape, would the BAU take the case? And how would he explain it if it really was Arthur and they saved him? 

“Merlin?”

“I-yes. I think I recognize it,” Merlin stammered. He wanted to continue but he didn’t know how, and then he spotted Dr. Reid looking at him inquisitively and that made it worse. He panicked. “I just…I never thought I’d hear it again.”

The rest of the flight was a blur for Merlin. He answered Hotch’s questions as best as he could, considering he knew nothing about Arthur’s existence in the 21st century. The story Merlin settled on was that he’d dated Arthur briefly during a study abroad exchange to England and that he hadn’t heard from him since, which he hoped would explain the huge holes in his knowledge. His home? His place of work? His relationship to Merlin? All blanks. When the interrogation was over, Hotch dismissed him with a curt nod and Merlin was stumbling back to his seat, trying not to vomit and trying not to notice the tender, concerned expression plastered on Dr. Reid’s face.

“Are you okay?” Reid asked, but it was obvious Merlin wasn’t. Something fundamental in him had shifted, a small piece of him had been broken or mended and Reid wasn’t sure which, so he just took Merlin’s graceful hand in his and traced flowers onto the back of it, hoping he was offering some sort of wordless comfort. “Do you want to talk about it?”

Merlin shook his head no, but the words were already tripping out of him. “I...he. I need to save him. I can’t let this be...can’t let this be the end. If something happens to him, I...I couldn’t bear it.”

“You love him? This man?” Reid said slowly, and though Merlin was having a hard time processing anything outside his own head, he could see the hints of pain and longing Reid was fighting to push down.

“I don’t know,” Merlin answered, his breath starting to slow. “I did, once, but it’s been such a long time. It feels like forever ago…”

And now that he was interrogating it, Merlin had loved Arthur, loved him with all his heart, but had Arthur loved him back? They had been the fiercest friends, sure, but neither had actually confirmed the thing Merlin suspected lied between them. He never confessed his heart’s feelings directly because he couldn’t bear to hurt Gwen, and he’d always thought it had been the same for Arthur. They’d only kissed once, as Arthur lay dying in Merlin’s arms, and can one kiss sustain a millenia?

Merlin became shivery, the fear setting in that he couldn’t save Arthur and even if he could, his king might not reciprocate his feelings. He couldn’t bear the horror of it, that nightmare of rescuing the man who had visited each of his dreams only to be greeted with a hug and a friendly pat on the back. He started to shake, and Reid moved instantly to comfort him.

“We’ll get him back, Merlin,” Reid said. “We’ll save him. I promise.” 

Merlin didn’t know, couldn’t have, that Reid had been in his shoes once. The similarities were striking. When Maeve had been taken, Reid had only recognized her from her voice. When Maeve had been taken, he’d known those same shivers, the shakes that had started in his core and hadn’t truly left him for months after the kidnapping. When Maeve had been taken, Reid’s friends had made the same promise to him: “We’ll get her back.” 

Maybe Reid could keep his promise.


End file.
